WASHINGTON — Former Secretary of State Hillary Rodham Clinton endorsed President Barack Obama’s attempt to win congressional approval of a military strike in Syria, saying today that any move by the Assad regime to surrender its weapons to international control would be an “important step.” But Clinton cautioned that the removal of its chemical weapons stockpile should not be an “excuse for delay and obstruction” by Syria. Clinton met with Obama at the White House as the administration sought to sway skeptical lawmakers in Congress to approve a plan to punish Syria’s government for last month’s chemical weapons attack. The former first lady offered her first public statements on the Syrian crisis, adding her voice to a series of Obama allies who have supported the military action. “I will continue to support his efforts and I hope the Congress will as well,” Clinton said at forum on wildlife trafficking, an issue that was one of her priorities at the State Department.